Question

The first DNA base used as a template for RNA synthesis is called the site.

a. true
b. false

Answer 1

The statement provided is false. Transcription starts at a region known as the promoter, not at a 'site' referred to as the first DNA base. The first base where RNA synthesis begins is at the +1 site or the initiation site of transcription.

Step-by-step explanation:

The statement 'The first DNA base used as a template for RNA synthesis is called the site.' is false.

RNA synthesis, or transcription, begins at a specific region of the DNA called the promoter. The enzyme RNA polymerase binds to this site to form a closed complex and then unwinds the DNA, exposing the template strand at the initiation site. The first DNA base where the RNA nucleotide is transcribed is referred to as the +1 site, or the initiation site. Nucleotides before this are upstream, and those after are downstream. Thus, the term 'site' does not refer to the first DNA base but rather to the location in the DNA where the transcription machinery assembles and begins creating RNA.

Answer 2

The statement is false; the first DNA base used as a template for RNA synthesis is part of the +1 site, known as the initiation site, not merely 'the site'.

Step-by-step explanation:

The statement in question is false. The first DNA base used as a template for RNA synthesis is not called the site. Instead, the nucleotide pair in the DNA double helix that corresponds to the site from which the first 5' mRNA nucleotide is transcribed is called the +1 site, or the initiation site. The actual process of RNA synthesis begins with the RNA polymerase enzyme binding to a specific sequence called the promoter. Only after this does the enzyme start transcribing RNA from the template strand of DNA, creating a new RNA molecule that is complementary to the template strand.